OPT: propseg: changed flag o --> ofolder (issue #623)
OPT: propseg: changed flag o --> ofolder (issue #623)

Former-commit-id: 88ef6407ec0d926a0345e1279385fdf9f4e0993e
Former-commit-id: 189766ba8027063527aac019576261de371bf686
3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox,3324fr/spinalcordtoolbox